Rep. Peter King (R-N.Y.) says China may have delayed or altered the images.
The first lady and her daughters will take a weeklong trip to China later this month.
The online resume site pledged to limit government censorship.
"Our two countries should be expanding media exchanges," Jay Carney said.
Baucus is expected to cruise to Senate confirmation.
Sen. Max Baucus appears to be on a glide path to become the next ambassador to China.
The Montana Democrat laid out a broad agenda during his confirmation hearing on Tuesday before the Senate Foreign Relations Committee. His plan is focused on promoting economic cooperation, security and human rights issues between the United States and China.
"It is imperative that America be deeply involved in the Asia-Pacific," Baucus said.
The State Department on Sunday criticized the conviction of Xu Zhiyong.
U.S. trade officials said they made strides on several key economic issues during meetings in China this week.
U.S. Trade Representative Michael Froman and Commerce Secretary Penny Pritzker said Friday that they reached agreements with Chinese officials on intellectual property rights, government procurement, and regulatory obstacles.
Top Obama administration officials are heading to China next week to discuss a broad range of economic and trade issues.
Commerce Secretary Penny Pritzker and U.S. Trade Representative Michael Froman will travel to Beijing to meet with Chinese Vice Premier Wang Yang as they head up the U.S.-China Joint Commission on Commerce and Trade (JCCT) on Dec. 19-20.
Michelle Obama used the naming of a giant panda cub to celebrate ties with China.